Process for the recovery of ketones and glycols from fermentation

ABSTRACT

A method of obtaining ketones from a fermentation process may include collecting an off-gas and a fermented broth from a fermenter, transferring the off-gas from the fermenter to a ketone recuperation module and the fermented broth to a fluid separating module, and isolating the ketones from both the off-gas and the fermented broth. The off-gas and the fermented broth may both comprise a ketone

BACKGROUND

Microbial fermentation produces a number of industrially-relevantcompounds that may be used as feedstock for a diverse range ofapplications for polymer manufacture. Compounds of interest aregenerated as components of broth and off-gas exiting a fermentationvessel as product streams. Fermentation broth and off-gas are complexmixtures containing a wide range of components with very differentcharacteristics, such as cellular biomass, insoluble solids, water,organic matter, inorganic and organic ions, and incondensable gases. Thechallenge lies in isolating product compounds from the variousimpurities, while minimizing time and energy costs associated withprocessing.

SUMMARY

This summary is provided to introduce a selection of concepts that arefurther described below in the detailed description. This summary is notintended to identify key or essential features of the claimed subjectmatter, nor is it intended to be used as an aid in limiting the scope ofthe claimed subject matter.

In one aspect, embodiments disclosed herein relate to methods ofobtaining ketones and glycols from a fermentation process, the methodincluding: collecting an off-gas and/or a fermented broth from thefermenter, wherein the off-gas comprises a ketone, and wherein thefermented broth comprises one or more of glycol or ketone; andperforming at least one of: transferring the off-gas from the fermenterto a ketone recuperation module; or transferring the fermented broth toa fluid separating module; and isolating one or more of: the ketone fromthe off-gas; and the glycol from the fermented broth.

Other aspects and advantages of the claimed subject matter will beapparent from the following description and the appended claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a flow diagram of a fermentation process in accordance withembodiments of the present disclosure.

FIG. 2 is a flow diagram of a column absorption-based purification offermenter off-gas in accordance with embodiments of the presentdisclosure.

FIG. 3 is a flow diagram of a distillation process in accordance withembodiments of the present disclosure.

FIG. 4 is a flow diagram of a pretreatment process of a fermented brothin accordance with embodiments of the present disclosure.

FIG. 5 is a flow diagram of a distillation process in accordance withembodiments of the present disclosure.

FIG. 6 is a flow diagram of a reactive distillation process inaccordance with embodiments of the present disclosure.

FIG. 7 is a flow diagram of a reactive extraction process in accordancewith embodiments of the present disclosure.

FIG. 8 is a flow diagram of a thin-film evaporation process inaccordance with embodiments of the present disclosure.

FIG. 9 is a flow diagram of a salt removal process of a fermented brothin accordance with embodiments of the present disclosure.

FIG. 10 is a flow diagram of a fermentation purification process using areactive distillation process in accordance with embodiments of thepresent disclosure.

FIG. 11 is a flow diagram of a fermentation purification process using areactive extraction process in accordance with embodiments of thepresent disclosure.

FIG. 12 is a flow diagram of a fermentation purification process using athin-film evaporation process in accordance with embodiments of thepresent disclosure.

FIG. 13 is a flow diagram of a fermentation purification process using apretreatment module in conjunction with a distillation module inaccordance with embodiments of the present disclosure.

FIG. 14 is a flow diagram summarizing various module arrangements inaccordance with embodiments of the present disclosure.

FIG. 15 is a flow diagram of a reactive distillation process inaccordance with embodiments of the present disclosure.

FIG. 16 is a flow diagram of a reactive extraction process in accordancewith embodiments of the present disclosure.

FIG. 17 is a flow diagram of a thin-film evaporation process inaccordance with embodiments of the present disclosure.

DETAILED DESCRIPTION

In one aspect, embodiments disclosed herein relate to processes toseparate and purify ketones and glycols produced by microbialfermentation. In one or more embodiments, methods in accordance with thepresent disclosure may be used to recover organic fermentation productssuch as ketones and glycols from aqueous solutions having variousconcentrations of salt.

The use of fermentation processes in biorefineries is being used todevelop renewable raw materials for industrial production of plasticsand other fine chemicals. Scaling these processes up to commerciallyrelevant scales presents a number of challenges from establishingoptimum microbial growth conditions, in addition to the isolation of thepure biologically-derived products from complex mixtures of salts andorganic materials obtained from fermentation tanks.

Methods in accordance with the present disclosure may utilize renewablefeedstocks that are converted, by fermentation, to a number ofcommercially relevant products that are isolated from the off-gas and/orbroth exiting the fermenter. Products in accordance with the presentdisclosure may include, for example, ketones, alcohols, and glycols,which are made using metabolic pathways harnessed by biotechnologicalprocesses. In one or more embodiments, fermentation processes mayproduce glycols and ketones in fermentation broths and/or off-gasstreams. Compared to conventional process for the production of thesechemicals, the compositions of the streams have a unique nature,particularly due to the presence of the target products, highconcentrations of water, and the presence of salts in the fermentedbroth. As a result, fermented product streams contain impurities andby-products that are distinct from those typically associated withindustrial chemical production. Methods in accordance with the presentdisclosure address these differences in the purification process.

With particular respect to FIG. 1, a simple fermentation setup ispresented. A feedstock stream 102 is introduced into fermenter 104,which contains a selected media tailored for the particularmicroorganism being cultivated. For example, a feedstock stream 102 maycontain water, sugar, salts, and various organic and inorganic nutrientmixtures. For aerobic fermentation, an air supply 106 may be introducedinto the fermenter to provide an oxygen source. As fermentationprogresses, an off-gas stream 108 may be generated containingincondensable gases, water, various ketones, aldehydes, and alcohols,and a number of trace contaminants that exits the fermenter. Fermentedbroth 110 may also be captured, which contains various concentrations ofwater, glycols, ketones, alcohols, salts, carboxylic acids, organicmatter, and inorganic matter.

Methods in accordance with the present disclosure are directed toprocesses to separate and purify industrially-relevant compounds such asketones and glycols produced during fermentation, which may be recoveredin off-gas and fermented broth mixtures obtained from a fermentingvessel. Following recovery, the output streams may be treatedseparately. In some embodiments, methods include isolating volatilecompounds from incondensable gases and other impurities through a numberof gas separation technologies. Volatile compounds may then be processedfurther to recover and isolate organics such as ketones.

In one or more embodiments, fermented broth may be transferred from afermenter to a fluid separation module where various purificationtechnologies may isolate valuable products such as glycols, alcohols,and other components. In some embodiments, fermented broth may bepretreated prior to forwarding to the fluid separation module, using anumber of techniques including sterilization, filtration, salt removal,and concentration. Volatiles in the fermented broth stream may betransferred to the gas separation module and combined with the off-gasproducts in other embodiments.

Methods in accordance with the present disclosure may include the use offluid separation modules that are tailored to the separation ofcomponents from a fermented broth containing salts. The presence ofsalts in broth may complicate the use of distillation and otherseparation techniques, because such techniques may utilize the removalof water that can generate solids and other scales and/or may inducecorrosion and other negative effects.

Off-Gas Separation and Ketone Recovery

In one or more embodiments, processes and systems in accordance with thepresent disclosure may include a module or series of modules forpartitioning an off-gas stream received from a fermenter into itsconstituent components. Off-gas generated from a fermenter may containlarge proportions of incondensable gases such as O₂, N₂, and CO₂. GasesO₂ and N₂ are often the return from an air supply injected into thefermenter, while CO₂ may be generated as a byproduct of microbialmetabolism. As the off-gas product stream is processed, the removal ofincondensable gases may be required to recover other valuable componentsfrom the product stream. In some embodiments, the off-gas stream may beprocessed into its constituents, for example, to separate and purifyketones from other components such as incondensable gases.

Off-Gas Separation Module

In one or more embodiments, processes and systems in accordance with thepresent disclosure may use absorption-based or condensation-basedpurification techniques to process fermenter off-gas (108 in FIG. 1).With particular respect to FIG. 2, off-gas separation technologies inaccordance with the present disclosure may include an absorption module200. Absorption separation may proceed by transferring an off-gas stream202 from a fermenter (stream 108 in FIG. 1) to the bottom of anabsorption column 204, which is then placed into contact with anabsorption agent 206 (such as water) introduced at the top of a column.Separation of the product mixture occurs as incondensable gases 208(such as CO₂, N₂, and O₂), which have limited affinity for theabsorption agent, travel through and exit the column. The remainingproduct stream 210 exiting the column 204 contains soluble componentsfrom the gaseous feed 202 that may include water, ketones, other speciesof interest, and small quantities of incondensable gases. There are manysuitable candidates for the absorption agent 206, such as water if theketone has a low molecular weight.

Ketone Recuperation Module

The soluble components 210 obtained from the absorption column mayinclude oxygenates, ketones, alcohols and other oxygenates, traceamounts of glycol, and acids, which are expected to be in a liquidmixture with absorbent as well as a very small quantity of incondensablegases. There are a variety of methods by which the ketones may berecovered from the diluted solution of soluble components 210, includingfor example distillation, evaporation, liquid-liquid extraction,pervaporation, etc. In one or more embodiments, the soluble components210 may be forwarded to distillation column such as that discussed belowwith respect to FIG. 3.

With particular respect to FIG. 3, an embodiment of a ketonerecuperation module 300 is shown. In this example, the liquid stream 302coming from an off-gas separation module (stream 210 in FIG. 2, forexample), which may contain a mixture of solvent, ketones, alcohols,water, acids, and trace amounts of glycols and incondensable gases, isfed into a distillation column 304, wherein the non-volatile (and oftenaqueous) component leaves as a bottom stream 312. The bottom stream 312may contain mixtures of water, alcohols, ketones and other oxygenates,acids, and/or glycols in various concentrations. The overhead stream 305from distillation column 304 may be cooled upon exiting the column,using a heat exchanger 306, for example. In some embodiments, condenser306 may be followed by a reflux tank 308 to separate incondensable gases314 (such as carbon dioxide, nitrogen, and oxygen) from ketones andother volatile components in stream 316. Part of the non-volatilecomponents in flux 316 may be returned to the overhead of distillationcolumn 304 for additional reflux in some embodiments. In one or moreembodiments, ketone 316 can also be recovered in a side stream fromcolumn 304, below a pasteurization region.

The bottoms 312 of the ketone recovery column 304, which may contain thesolvent (such as water), acids, and glycols, may be sent to wastewatertreatment or may be treated to remove the contaminants from the solvent,which may be recirculated back to the absorption column 304 in someembodiments. Treatment may be done by distillation, evaporation,adsorption, liquid-liquid extraction or other unit operation known bythe state of the art. The non-condensable gases 314 from the overheadstream 305 may optionally be cycled to an absorption module, discussedwith respect to FIG. 2, in order to recover residual losses of theketone in some embodiments. Thus, in one or more embodiments,technologies used to process off-gas components may include distillationcoupled with partial condensation as discussed at 306 in FIG. 3.

Fluid Separation and Glycol Recovery

In one or more embodiments, processes and systems in accordance with thepresent disclosure may include one or more fluid separation modules thatpartition fluid streams obtained from a fermenter into their variousconstituent components. In some embodiments, fluid separation modulesmay be used to isolate ketones, glycols, and other industrially-relevantcompounds from fermentation processes.

Fluid Separation Modules

Processes and systems in accordance with the present disclosure maycontain one or more fluid separation modules to separate a fermentedbroth stream obtained from a fermenter into its various constituentcomponents. Fermented broths have a number of characteristics andcomponents that are unique when contrasted with other industrialprocesses used to generate feedstocks. In addition to water andcompounds of interest, a fermented broth stream may contain solids,salts, minerals, carboxylic acids, phenolic compounds, proteins, andunconverted sugars. Examples of solids includes precipitated sugars suchas arabinose, mannose, glucose and its oligomers, xylose and itsoligomers, and others; various organics such as succinic acid andprecipitated lignin; and biomass including live and dead bacteria,yeast, and other microbes.

In fermentation broths, salts are often used to create favorableconditions for microorganisms, and are often present in downstreamprocesses in noticeable concentrations. Salt precipitation can become anissue, particularly through the formation of insoluble salts or by waterevaporation. Precipitated salts can cause flow issues in addition toheat transfer surface fouling, which can result in time and financialexpense to address. However, it is also envisioned that in one or moreother embodiments, such salt removal is not necessary, and glycol isrecovered from a salt-containing fermented broth. In such cases, careshould be taken such that the water concentration of the broth ismaintained above the solubility limit of the salts, in order to avoidsalt precipitation. Moreover, materials that contact fermentationstreams should be selected with consideration to the types of salts inthe production streams. For example, some salts such as chlorides, areknown by their high corrosion potential, and equipment handling productstreams with these salts should be resistant to corrosion.

Methods in accordance with the present disclosure may be used to removeproducts of interest from product streams containing a range of saltconcentrations using one or more fluid separation modules that mayoperate by a number of techniques that may include distillation,reactive distillation (RD), reactive extraction (RE), thin-filmevaporation (TFE), short path evaporation (SPE), continuouschromatography, and batch chromatography. Further, in one or moreembodiments, methods of separating components from a fermented brothhaving a high concentration of salts may involve the use of a separatingagent that enhances the separation of products of interest such asketones and glycols from a fermented broth. A number of possibletechniques are discussed in turn as follows.

Distillation Series

Methods of glycol recovery from aqueous solutions may includedistillation by one or more distillation columns. When salts are presentin the broth, their precipitation in process equipment, eitherchemically or as a result of water evaporation, may cause flow issues inthe process, surface fouling, and often lead to downtime to addressthese issues. Salts are required for creating favorable fermentationconditions for microorganisms, and are often present in downstreamprocesses in non-negligible concentrations.

In one or more embodiments, a distillation series may be used to purifyglycol and other target compounds, following the removal or reduction ofsalt concentration using a salt removal module or other pretreatmentmodule, discussed below. In some embodiments, a product stream leaving asalt removal module may be separated using a distillation series havingtwo or more distillation columns to recover organics such as glycols.With particular respect to FIG. 5, a sample arrangement of distillationcolumns in a distillation module 500 is shown. As a product stream 502(which may include, for example, water, lighter organics, glycol, andheavier organics) enters a first distillation column 504, water andlighter organics may be removed as an overhead stream 506. The bottomstream 508 contains compounds such as glycol and other heavies, whichare transferred to a second distillation column 510 in the series.Glycol and other compounds exit the second column 510 as an overheadstream 512, while heavies are ejected as bottom stream 514.

Reactive Distillation

Reactive distillation is a process intensification technique, in which achemical reaction and a distillation occur in a single equipment. In oneor more embodiments, fluid separation modules may include the use ofreactive distillation to separate polyols such as glycol from afermented broth by reacting the polyol with a separating agent having acarbonyl species (e.g., aldehydes or ketones) that reacts with polyolsto form the corresponding acetal. Acetals in accordance with the presentdisclosure include ketals or acetals prepared from the reaction ofcarbonyl species including respectively ketones or aldehydes withalcohols and include compounds historically referred to as ketals andacetals. Further, acetals in accordance with the present disclosureinclude cyclic acetals such as dioxolanes and dioxanes. Acetal speciessuch as dioxolanes are often more volatile than the corresponding polyoland have a reduced capacity for hydrogen bonding, allowing the acetal tobe separated from the solution in the reactive distillation column. Itis also envisioned that “acetal” as used herein may represent aheterogeneous mixture of acetals generated from multiple carbonylspecies present in a product stream, including acetals generated fromboth ketones and aldehydes.

With particular respect to FIG. 6, an embodiment of a fluid separationmodule 600 incorporating a reactive distillation column is shown. In theembodiment, a broth stream 602 (which has been clarified and optionallyconcentrated) is transferred to reactive distillation column 604, whileseparating agent 606 (a carbonyl species, for example) is fed into thecolumn 604 at another location. In one or more embodiments, glycolpresent in the broth stream 602 reacts with the separating agent 606 inthe column 604, transforming glycol to the corresponding acetal form bymeans of a reaction with the separating agent in the presence of acatalyst. In the case of the reaction of glycol and a carbonyl species,a cyclic acetal is formed. For example, monoethyleneglycol reacts withformaldehyde forming 1,3-dioxolane and water, while andmonoethyleneglycol reacts with acetone giving2,2-dimethyl-1,3-dioxolane. The acetal forms of glycol are more volatilethan water, and may be distilled as an overhead stream 608 together,often with some concentration of residual carbonyl species. Conversionto acetals may occur in the presence of a catalyst in some embodiments.Catalysts may include mineral acids such as hydrochloric acid, or ionexchange resins. Acetal-forming reactions are equilibrium reactions andstoichiometric excesses of carbonyl species may be used to drive thereaction to higher conversion rates in some embodiments.

In one or more embodiments, a portion of water may leave the reactivedistillation column 604 with acetal obtained as overheads 608, due tothe formation of a minimum-boiling azeotrope between acetal and water.Nevertheless, the majority of the water may remain at the bottom of thecolumn 604 to maximize the solubility of the salts in the remainingbroth, which may exit the column as bottom stream 610. The reactivedistillation column overheads 608 are passed to a second distillationcolumn 612, where the unreacted separating agent (i.e., a carbonylspecies such as aldehyde or ketone), is recovered as an overhead stream614 and recycled back to the first column 604.

The bottoms 616 from the second column 612 are sent to a thirddistillation column 618 (hydrolysis column), where water 620 is added tohydrolyze the acetal to obtain the corresponding glycol. The bottomstream 624 of the hydrolysis column 618 is a water/glycol mixture, andthis is ultimately sent to a final distillation column 626 to removewater as an overhead stream 628, while glycol is obtained at 630. In oneor more embodiments, ketones or aldehydes obtained from a fermentedbroth as a co-product of the fermentation may be used as separatingagent 606 used for reactive distillation.

In some embodiments, flow stream 630 may be sent to a final distillationcolumn where the heavy compounds are withdrawn in a bottom stream, whilepurified glycol is obtained as an overhead stream. In some embodiments,purified glycol may be collected and stored following cooling by a heatexchanger. While glycol is shown as a representative polyol in thisexample, it is envisioned that the process may be adapted to captureother polyol species containing two or more available alcohol groupsand/or two or more carbon atoms, 1, 3 propylene glycol, for example.

Reactive Extraction

In one or more embodiments, reactive extraction may be used as a processintensification technique, in which a chemical reaction and a solventextraction occur in a single combined process to separate glycols andother organics. Similar to reactive distillation discussed above,reactive extraction operates by modifying the solubility and volatilityof glycols by reacting them with a separating agent to generate thecorresponding acetal or cyclic acetal. Further, a solvent is introducedinto the reactive distillation column, which extracts hydrophobic andnonpolar species from the aqueous fermented clarified broth stream if apretreatment module is used. Reactive extraction utilizes the change inaffinity of the converted glycol (dioxolane, for example) for theorganic solvent phase, aiding separation. Hydrolysis of the convertedglycol then regenerates the glycol product downstream.

With particular respect to FIG. 7, a reactive extraction module 700 isshown. A fermented broth stream 702 (which has been clarified and/orconcentrated in some embodiments) is transferred to reactive extractioncolumn 704. The reactive extraction is then initiated by convertingglycol to an acetal using separating agent 706, such as aldehyde orketone, which is combined with the broth 702 in reactive extractioncolumn 704. Thereafter, instead of distilling the acetal from theaqueous mixture as described with respect to FIG. 6, the dioxolane isextracted using a solvent 708, which is transferred from column 704 asstream 710 containing reactant, acetal, solvent, and a fraction ofwater.

The solvent-rich phase 710, containing the acetal, is then withdrawn andsent to a distillation column 712 to recover the solvent as stream 714.In tower 712, acetal is recovered as an overhead stream 716 and thesolvent removed at the bottoms 714 is recycled back to the reactiveextraction column 704. The acetal flow is sent to a reactivedistillation column 720, called hydrolysis column, where water 718 isadded to revert the acetal back to glycol, which leaves as bottom stream722 as a mixture with water. The overhead stream 724 contains mainlyreverted separating agent, such as an aldehyde or ketone, which may berecycled back to the reactive extraction column 704. The bottoms 722 ofthis hydrolysis column is, once again, a water and glycol mixture, andthis is ultimately sent to a final distillation column 726 to generatean overhead stream 728 containing water and a bottom stream 730containing glycol. In one or more embodiments, flow stream 730 may besent to a final distillation column where heavy compounds are withdrawnin a bottom stream, while glycol is obtained in an overhead stream. Insome embodiments, purified glycol may be collected and stored followingcooling by a heat exchanger. One advantage of configurations such asthat described is that ketones already present in the process as aco-product of the fermentation, may be used as a separating agent 706for reactive extraction.

The solvent may be chosen in order to promote recovery of the acetal inthe organic phase. In one or more embodiments, organic solvents mayinclude toluene, ethylbenzene, o-xylene, and the like. The aqueous phase731 from the reactive extraction column 704 may contain water, salts,sugars, separating agent, acetals, and solvent in some embodiments.After leaving reactive extraction column 704, aqueous phase 731 may betransferred to distillation column 732 equipped with a decanter 736. Theseparating agent, acetal, and solvent are recovered in the organic phaseof the decanter 736 as stream 738 and may be recycled to the solventrecovery column 712 in some embodiments. One advantage of thisconfiguration is that ketones are already present in the process as aco-product of the fermentation, may be used as separating agent 706 usedfor reactive extraction. For example, bottoms 731 from the reactiveextraction column 704 may be sent to distillation column 732 in order torecover solvents, reactants, and to eliminate residual water. Forexample, bottoms 731 may be separated into an overhead stream 733, whichmay be cooled using heat exchanger 734 and passed to decanter 736 toseparate the overhead stream 733 into a fraction 738 containing organicssuch as aldehydes, ketones, acetals, and solvent, and a water fraction740. Water and other heavies that exit column 732 as the bottoms may berecovered as stream 742.

Evaporator Modules

In one or more embodiments, a fluid separation module may incorporateone or more thin film evaporators and/or short path evaporators torecover organics and water, while salts and heavier components such assugars are separated. In some embodiments, a fermented clarified brothstream may be concentrated in a concentration module, and transferred toa first stage evaporator to recover a stream enriched in glycol andwater. A second stage evaporator, working at a lower pressure may alsobe added to the system to help to recover glycol from the liquid of thefirst evaporator. In this case, the evaporated flow from the secondevaporator is condensed and pumped back to the first evaporator and theliquid, which now contains a higher salt concentration, is purged fromthe system.

The thin-film evaporators prevent salts from fermented broths fromsticking to heated surfaces. This technology also has several advantagessuch as short residence time, high heat transfer coefficients due toturbulent flow, ability to handle high solids concentrations and viscousmaterials, and less product decomposition, resulting in higher yields.Constructively, a thin film evaporator is formed from a sealed vesselequipped with a heating jacket. The feed flows down the evaporator wallby gravity, with or without the assistance of mechanical wipers, andforms a thin film that covers the evaporating surface and drives heaviesdown to a bottom exit. Due to the heating and applied vacuum, thevolatile components are evaporated and then liquefied in an externalcondenser. The components that are not evaporated are pumped out ordischarged.

In some embodiments, short path evaporators can be used for glycolrecovery. Also known as molecular distiller, a short path evaporator(SPE) is very similar to thin-film evaporator, except that it contains acondenser concentrically fixed within the apparatus. A SPE generallyconsists of two concentric cylindrical bodies, in which one act as anevaporation surface and the other acts as a condensation surface. Thefeed of liquid material to be concentrated/distillated falls through theheated wall and partially vaporizes. As steam is generated, itencounters the cold wall and condenses.

In some embodiments, a separating agent such as a salt entrainer isintroduced to the broth medium to maintain salts in the liquid phase,during thin film evaporation and short path evaporation for example,while lighter organics such as ketones and glycols are evaporated andcollected by the thin film evaporator. Entrainers in accordance with thepresent disclosure are viscous products that are usually of a highermolecular weight than the target ketone or glycol compound. Due to theviscous nature of the chemicals, feedstock sugars or glycerol can beused as salt entrainers that maintain salts in the liquid phase, whilevolatile components and water vaporize from solution. In one or moreembodiments, salt entrainers (such as glycerol in this example) may beadded to a fermented clarified broth at an excess concentration, suchthat salts are kept in the liquid phase and entrained to the bottom ofthe evaporator.

With particular respect to FIG. 8, an embodiment of a fluid separationmodule utilizing an arrangement of thin film evaporators is shown. Afermented broth 802 (which has been clarified and optionallyconcentrated in some embodiments) may be combined with a salt entrainerfrom stream 810 and transferred to a thin-film evaporator 812 toevaporate off the glycol, light components, and water, while the saltsare entrained by the separating agent, and carried to the bottom exit ofthe evaporator at 836 along with other components such as salts andsugars. The separating agent/entrainer also prevents the salts fromsticking to the walls of the evaporator and enhances the glycolrecuperation in the evaporated stream.

If the separating agent/entrainer still contains a considerable quantityof glycol, a second evaporator 838, working at a lower pressure may beadded to recover glycol from the liquid coming from the first evaporatoras stream 836. In this case, the evaporated flow 842 from the secondevaporator 838, which is rich in the salt entrainer but also containsglycol, is passed through condenser 840 and pumped back to the firstevaporator 812. Any unrecycled separating agent leaves as bottom of thesecond thin film evaporator as stream 844. Stream 844 is often rich insalt entrainer and salts, and may be considered a waste stream in someembodiments. In fermentation broths containing high concentrations ofsugars and/or glycerol, the amount of makeup 810 needed for recyclingthe entrainer to stream 842 may be negligible to none.

The distillate product 814 from the first evaporator 812 in any of theabove embodiments may be enriched in glycol, light organics, saltentrainer, and water, which is then sent to a partial condenser 816where the glycol is condensed as stream 820, while water, lightorganics, and some glycol exit as overhead stream 818. Stream 820containing glycol, salt entrainer, light organics, and water may then betransferred to a distillation series containing columns 822 and 830 toproduce the purified glycol. For example, stream 820 is transferred tocolumn 822 which is separated to overhead 824 containing water and lightorganics, and bottom stream 826 containing glycol, heavy organics, andsalt entrainer. Stream 826 is then polished in column 830 to generate aglycol product stream 832 and separated heavies and entrainer fraction834. In an alternative configuration, the distillate coming from thefirst evaporator 812 is completely condensed in the condenser 816 andafter is sent directly to a distillation series such as columns 822 and830. Here, the first distillation column 822 removes water at the topproduct 824 and its bottom product 826 is sent to the second column 830,where glycol is recovered at the overhead 832 and the bottom 834containing the heavies is purged from the process.

While the examples presented include entrainer, it is also envisionedthat fluid separation modules incorporating thin film evaporation may beperformed without separating agents, or by using endogenous separatingagents such as a sugars by modifying the concentration of sugars appliedto and leaving the fermenter.

Chromatography Modules

Fluid separation modules in accordance with the present disclosure mayinclude one or more chromatographic modules. Chromatographic methods inaccordance with the present disclosure may include the separation ofsolutes in a mixture based on differences in migration rates through atwo phase system. Although it may be used as an analytical technique foridentifying components in a mixture, chromatography may be used on acontinuous large scale to separate and purify the products in varioussyntheses.

In batch chromatography, a pulse of the feed mixture is injected into acolumn packed with an adsorbent and a continuous flow of a solventpasses continuously through the column. Due to the difference ofaffinity of the adsorbent to the various solutes, they migrate throughthe column at distinct speeds and are thus separated. However, becausebatch operation is often inefficient, requiring large amounts of solventand making an inefficient use of the column throughout separation,continuous chromatographic systems have been developed to provide moreefficient operation resulting in higher productivities.

In one or more embodiments, the chromatography module may be configuredto perform continuous chromatography. The large-scale production ofchromatographic products may require continuous and autonomous systemsthat offer higher efficiency and lower solvent consumption than batchunits. The simulated moving bed is an established continuouschromatographic technique used in several fields. Several othercontinuous systems have also been developed such as True Moving Bed(TMB), simulated moving bed (SMB), pseudo-SMB, intermittent-SMB,supercritical SMB, Gradient SMB, POWERFEED™, MODICON™, variable externalstreams systems, VARICOL™, Multi-Feed, and others.

In one or more embodiments, a fermented broth may be processed by a saltremoval module, and passed through a chromatography module to generateat least one fraction containing purified glycol and at least onefraction containing other fermentation co-products. In some embodiments,operation of the chromatography module may be carried out batch-wise orby a continuous process.

Salt Removal Module

Fluid separation modules in accordance with the present disclosure mayinclude processing a fermented broth to obtain glycols and other speciesof interest by sequential treatment by a salt removal module to removingsalts and other ionic species, followed by treatment with a distillationseries to enrich for the target compound.

Salt removal modules in accordance with the present disclosure mayinclude a number of technologies such as filtration, precipitation, ionexchange, and electrodialysis. Salt removal pretreatment modules can beapplied separately or combined, depending on the characteristics of thebroth. As used herein, “salt removal” may include complete removal ofthe salt concentration from a liquid stream, or removal of a portion ofthe salt concentration.

In one or more embodiments, glycols and other species of interest may bepurified from a fermented clarified broth by removing salts using a saltremoval module followed by separation of glycols using a fluidseparation module. In some embodiments, methods may include purifyingglycols and other species of interest by removing at least a portion ofsalts using a pretreatment module

Filtration

Filtration technologies such as nanofiltration, may be used to removedissolved salts. Nanofiltration can separate multi-valent ions from aliquid stream with considerable efficiencies.

In one or more embodiments, salt removal methods may be used to removesalts from the fermented broth. With particular respect to FIG. 9 a saltremoval module incorporating a series of techniques is shown. Thefermented clarified broth stream 902 passes through a nanofiltration(NF) 904 generating a NF retentate 906. Once NF retentate is removed thestream is then transferred to an ion exchange section 908 which capturescharged species and produces a reduced salt stream 910.

Precipitation Module

Other techniques that may be used to reduce salt concentration includeprecipitation followed by a solid separation step. Precipitation mayrefer to chemical precipitation or evaporative precipitation(crystallization, for example). In chemical precipitation, a compoundforeign to the process is introduced, changing the solubility andcausing salts to precipitate. In evaporative precipitation orcrystallization, the solvent is removed beyond the solubility limits ofsalts, causing a portion of salts to crystallize and precipitate.Precipitated salts may then be removed by a number of techniquesincluding decantation, centrifugation, filtration, or other known formof solids separation.

Ion Exchange

In one or more embodiments, salt removal methods may include using ionexchange to remove a portion of salt from a fermented clarified brothstream prior to passage of the fluid through a fluid separation module.In ion exchange technology, a fermented clarified broth passes throughone or more ion exchange units, where ions of opposite charges areattracted and retained on the ion exchange resins. The removed ions arereplaced by other ions. The resins may be either cationic, anionic, ormixed-charged. Ion exchangers may be used in series, and may includecationic and anionic exchanger sections. Depending on thecharacteristics of the fermented broth, multiple ion exchange units maybe used, optionally with an evaporation step to concentrate theclarified solution between the series. After drawing ions from a streamthe resin progressively saturates, and the ion exchange units need to beregenerated using chemicals appropriate for the charge of the unit,including acids and bases, which generates an effluent. In oneparticular embodiment, ion exchange module may be preceded by ananofiltration unit. This technology is effective to partially removenon monovalent ions and can relieve the ion charges imposed to the ionexchange modules.

Electrodialysis

In one or more embodiments, salt removal may include one or moreelectrodialysis cells. Electrodialysis is a technique in which ions aretransported across an electrically-driven ion exchange membrane.Electrodialysis membranes may be either cation or anion-selective,allowing only same charged species to pass through, and rejectingopposing charges. In an electrodialysis cell stack, several membranes ofalternating selectivity are placed to maximize the retention of ions.Electrodialysis is also useful in that it does not require aregeneration step. In one particular embodiment, electrodialysis modulemay be preceded by a nanofiltration unit. This technology is effectiveto partially remove non monovalent ions and can relieve the ion chargesimposed to the electrodialysis modules.

Following the removal of salt by a salt treatment module, glycol andother species of interest may be isolated using a distillation column ordistillation series such as that discussed with respect to FIG. 5 andthe accompanying text.

Salt removal in accordance with the present disclosure may also includenanofiltration followed by ion exchange in some embodiments, or byprecipitation and/or nanofiltration followed by ion exchange in otherembodiments. In yet other embodiments, precipitation and/ornanofiltration may be performed and followed by electrodialysis. Inother embodiments, salt removal may be done by precipitation and/ornanofiltration followed by ion exchange and/or electrodialysis. Inaddition, in all the non-limiting embodiments previously described, awater removal step may be performed between modules, such as evaporationor membrane separation (reverse osmosis). While a number of examples arepresented for clarity, it is envisioned that the modular nature of thetechniques discussed above permit any combination of pretreatmentmodules and salt removal to be performed prior to and/or following theuse of fluid separation modules without departing from the scope of theinstant disclosure.

Pretreatment Processing of Fermented Broth

In one or more embodiments, a fermented broth must undergo a number ofpretreatments prior to processing by a fluid separation module.Pretreatment methods in accordance with the present disclosure mayinclude reducing solids and salt content of a fermented broth.

Pretreatment Modules

In one or more embodiments, a fermented broth from the bottom streamfrom a fermenter (i.e., broth 110 from fermenter 104 in FIG. 1) ispretreated prior to purification of glycols and other components indownstream processing in fluid separation modules. Pretreatment modulesmay be placed in line prior to a fluid separation module in someembodiments. Following processing by a pretreatment module and a fluidseparation module, the generated product stream may be sent to one ormore distillation columns or similar separation technology to isolatepurified glycols and other species of interest.

In some embodiments, pretreatment of a fermented broth may includesterilization and/or clarification to remove solids, biomass, andorganic matter. For example, the fermentation broth may contain solids,salts, minerals, carboxylic acids, aldehydes, phenolic compounds,furans, ketones, glycols, alcohols, proteins, and unconverted sugars.Examples of solids include precipitated sugars (arabinose, mannose,glucose and its oligomers, xylose and its oligomers, etc.), succinicacid, precipitated lignin, and biomass (bacteria or yeast cells). Thus,pretreatment of a fermented broth may include centrifugation to removecells and other precipitated solids alone or followed by one or morefiltration techniques including microfiltration, ultrafiltration, andnanofiltration to remove unconverted sugars, large molecules, and celldebris. In one or more embodiments, the clarification may be donewithout centrifugation and using one or more filtration techniques.

In one or more embodiments, cells and other solids obtained fromclarification techniques such as centrifugation may be washed to recoverthe glycol contained in the cell moisture. In other embodiment,centrifugation is followed by microfiltration and/or ultrafiltrationand/or nanofiltration to remove unconverted sugars, cell debris, andother solubilized large molecules. In some embodiments, clarification isdone by a microfiltration followed by ultrafiltration and/ornanofiltration.

The term “fermented clarified broth” which will hereinafter be usedmeans the fermented product whose cells and other solids have beenpartially or completely removed.

With particular respect to FIG. 4 a pretreatment module incorporating aseries of pretreatment techniques is shown. As fermented broth 402leaves the fermenter, the broth is centrifuged at 404 to remove solidsand biomass 406. The liquid fraction continues to microfiltration 408for further clarification, removing additional solids and biomass 407,before passaging to ultrafiltration (UF) 410, generating UF retentate412 before passing to nanofiltration (NF) 414 and generating a NFretentate (416) and a fermented clarified broth 415.

Light Organics Separation Module

In one or more embodiments, processes and systems in accordance with thepresent disclosure may include a ketone and light organics separationmodule to recover remaining ketone and light organics that may bepresent in the fermented clarified broth. Methods for ketone and lightorganics separation from the fermented clarified broth may includedistillation by one or more distillation columns, and/or evaporation inan evaporator system.

In one or more embodiments, one or more distillation columns may be usedto separate ketone and other lighter compounds from the fermentedclarified broth, following the removal of solids and cells using apretreatment module, discussed above. In some embodiments, a productstream leaving the pretreatment module may be separated using adistillation series having one or more distillation columns to recoverketone and light organics such as aldehydes and alcohols. As an example,with particular respect to FIG. 10, the fermented broth leaves thefermenter 1002 as stream 1005, which may then be pretreated using apretreatment module 400, which may remove cells, solids and a portion ofsolids and salts from stream 1005, which is then transferred todistillation column 1018. Distillation column 1018 may remove volatilessuch as dissolved incondensable gases, water, ketones and otherorganics, which may then be routed as stream 1016 and combined with thestream 1010 entering the distillation module 300 and processedaccordingly.

Concentration Module

In one or more embodiments, a concentration module may include adistillation series that may include a first distillation column thatconcentrates organics and other compounds in the fermented clarifiedbroth. A fraction of the water removed from the concentrated broth mayexit an overhead stream from the column, while the concentration ofsalts in the remaining concentrated stream remains below the saturationpoint, minimizing or eliminating possible salt precipitation.

The concentration step is not limited to a distillation column, otherkinds of technologies may be used such as multiple effect columns orevaporators, including thermal vapor recompression, mechanical vaporrecompression evaporators or a combination of multiple effect andthermal vapor recompression, or mechanical vapor recompression.

Additional treatment Processing of Products from Fermented Broth

Methods in accordance with the present disclosure may involve the use ofcolor and odor removal modules to polish product-containing streamsobtained from a fluid separation module or even between the stepsdescribed inside a fluid separation module. In some embodiments, colorand odor removal modules may be placed in line within a fluid separationmodule prior to final stage separation of glycol and other products,such as prior to passing a product-containing stream to a distillationcolumn or distillation series.

Color and Odor Removal Modules

In one or more embodiments, methods in accordance with the presentdisclosure may incorporate color and odor removal modules to polishstreams containing products of interest. Compounds such as residualsugars, aldehydes, ketones, phenolic compounds, furan derivatives andothers may introduce coloring that can negatively affect productquality, such as when product streams are heated in the downstreamseparation processes.

In one or more embodiments, one or more color and odor removal modulesmay be added to the processes in accordance with the present disclosure.Removal of coloring and UV absorbing impurities in accordance with thepresent disclosure may occur at any point in the purification process toobtain target compounds such as ketones and glycols, including afterpretreatment of a fermented broth by centrifugation and/or filtration,prior to, after or between the unit operations of the fluid separationprocesses, or combinations thereof. For example, the use of color andodor removal modules such as activated carbon beds and/or hydrogenationreactor and/or ultraviolet (UV) treatments may be placed prior to orfollowing a fluid separation module, including distillation, reactivedistillation (RD), reactive extraction (RE), thin-film evaporation(TFE), short path evaporation (SPE), continuous chromatography, andbatch chromatography.

In some embodiments, color and odor removal modules may include treatinga fermented clarified broth stream using one or more techniques such ascontacting the stream with an activated carbon bed, a hydrogenationcatalytic reactor, or exposing the stream to UV radiation. In someembodiments, an activated carbon bed may adsorb organics and othercompounds responsible for color, while in a hydrogenation catalyticreactor a stream of hydrogen is used to hydrogenate color precursorssuch as unsaturated organics and other color precursors. In someembodiments, hydrogenation catalytic reactor and treatment with UVradiation are placed before the final distillations to separatecompounds that may be formed.

Applications: Integrated Gas and Fluid Separation

In this section, embodiments of methods and systems to separate gasesand fluids obtained from a fermentation process are provided.

Example 1—Reactive Distillation

In a first example, a process in accordance with the present disclosureis used to isolate ketones and glycols from microbial fermentation usingreactive distillation. With particular respect to FIG. 10, fermenter1002 generates an off-gas stream 1004 that is transferred to absorptionmodule 200, described with respect to FIG. 2 and the accompanying text,which utilizes input water 1006 to absorb ketones and compounds ofinterest that exit the module as stream 1010, while allowingincondensable gases 1008 (including CO₂, N₂, and O₂) to exit the column.Stream 1010 is then transferred to ketone recuperation module 300,described with respect to FIG. 3 and the accompanying text, whichgenerates stream 1012 containing the remaining incondensable gases(which may be recycled back to module 200 in some embodiments), andstream 1014 enriched in ketone.

The fermented broth leaves the fermenter 1002 as stream 1005, which maythen be pretreated using a pretreatment module 400, described in FIG. 4and the accompanying text, which may remove cells, and a portion ofsolids and salts from stream 1005, which is then transferred todistillation column 1018, which is a light organics separation module.Distillation column 1018 may remove volatiles such as dissolvedincondensable gases, water, ketones and other organics, which may thenbe routed as stream 1016 and combined with the stream 1010 entering theketone recuperation module 300 and processed accordingly.

The bottoms 1020 from column 1018 containing glycols and other productsof interest are transferred to another distillation column 1022 such asa multiple effect distillation column, which concentrates stream 1020 byremoving a water fraction 1024 as overheads, and transferring thebottoms 1025 to reactive distillation module 600, described with respectto FIG. 6 and the accompanying text. Following the module 600, a waterstream 1026 is generated in addition to the glycol enriched stream 1028.

In an alternative configuration, the glycol enriched stream 1028 fromthe bottom of the dehydration column 1022 is sent to a hydrogenationreactor where a catalyst uses a small flow of oxygen to hydrogenatecolor contaminants. After the hydrogenation, glycol is sent to adistillation column such as column 604 represented in module 600 (FIG.6).

Activated carbon can also be used to reduce color or odor. In one ormore embodiments, the glycol enriched stream 1025 from the bottom of thedehydration column 1022 is sent to an activated carbon bed, where thecolor and UV absorbers contaminants are adsorbed. In some embodiments,glycol enriched stream 1028 from module 600 may be sent to an activatedcarbon bed, where the color and UV absorbing contaminants are absorbed.The purified glycol may then be cooled and sent to storage.

While glycol is shown as a representative polyol in this example, it isenvisioned that the process may be adapted to capture other polyolspecies containing two or more available alcohol groups and two or morecarbon atoms, monoethylene glycol or propylene glycol, for example.

Example 2—Reactive Extraction

In another example, a process in accordance with the present disclosureis used to isolate ketones and glycols from microbial fermentation usingreactive extraction. The reactive extraction process is similar to thereactive distillation process, but differs in the manner in which theacetal is separated from the broth. Particularly, a reactant is added toa reactive extraction column, which converts glycol into acetal. Asolvent is also added in the reactive extraction column, and the acetaland part of the unreacted reactant are removed from this column by meansof extraction. Solvents used may have partial miscibility with water,but may be selected such that acetal has a higher affinity for thesolvent to aid partitioning away from the aqueous phase. Possiblesolvents are toluene, ethylbenzene and o-xylene. The solventcounter-currently contacts a fermented clarified broth in the column,extracting the dioxolane simultaneously while the reaction takes place.In some embodiments, the organic phase (solvent, acetal, reactant andother contaminants) leaves the column as a top stream, while the aqueousphase (water, solubilized salts and sugars, and part of the organics)remain at the bottom of the column.

With particular respect to FIG. 11, fermenter 1102 generates an off-gasstream 1104 that is transferred to absorption module 200, described withrespect to FIG. 2 and the accompanying text, which utilizes input water1106 to absorb ketones and compounds of interest that exit the module asstream 1110, while allowing incondensable gases 1108 to exit the column.Stream 1110 is then transferred to ketone recuperations module 300,described with respect to FIG. 3 and the accompanying text, whichgenerates stream 1112 containing the remaining incondensable gases(which may be recycled back to module 200 in some embodiments), andstream 1114 enriched in ketone.

The fermented broth leaves the fermenter 1102 as stream 1105, which maythen be pretreated using a pretreatment module 400, described in FIG. 4and the accompanying text, which may remove cells, solids and a portionof salts from stream 1105, which is then transferred to distillationcolumn 1118, which is a light organics separation module. Distillationcolumn 1118 may remove volatiles such as water, ketones, other lightorganics, and residual incondensable gases, which may then be routed asstream 1116 and combined with the stream 1110 entering the ketonerecovery module 300 and processed accordingly.

The bottoms 1120 from column 1118 containing glycols and other productsof interest are transferred to distillation column 1122, whichconcentrates stream 1120 by removing a water fraction 1124 as overheads,and transferring the bottoms 1125 to reactive extraction module 700,described with respect to FIG. 7 and the accompanying text. In one ormore embodiments, distillation column 1122 may be multiple effectdistillation columns or an evaporator series to concentrate stream 1120.Following the module 700, a water stream 1126 is generated in additionto the glycol enriched stream 1128.

In an alternative configuration, the glycol enriched stream 1125 fromthe bottom of the dehydration column 1122 is sent to a hydrogenationreactor where a catalyst uses a small flow of hydrogen to hydrogenatecolor and UV absorbers contaminants. After the hydrogenation, glycol maythen be sent to module 700. Activated carbon can also be used to reducecolor and odor. In another embodiment, the glycol enriched stream 1125from the bottom of the dehydration column 1122 is sent to an activatedcarbon bed, where the color and UV absorbers contaminants are adsorbed.In other embodiments, glycol enriched stream 1128 from module 700 may besent to an activated carbon bed, where the color and UV absorbingcontaminants are absorbed. Then purified glycol is cooled and send tostorage.

While glycol is shown as a representative polyol in this example, it isenvisioned that the process may be adapted to capture other polyolspecies containing two or more available alcohol groups and two or morecarbon atoms, monoethylene, monoethylene glycol or propylene glycol, forexample.

Example 3—Thin Film Evaporation

In the next example, a process in accordance with the present disclosureis used to isolate ketones and glycols from microbial fermentation usingthin film evaporation. With particular respect to FIG. 12, fermenter1202 generates an off-gas stream 1204 that is transferred to absorptionmodule 200, described with respect to FIG. 2 and the accompanying text,which utilizes input water 1206 to absorb ketones and compounds ofinterest that exit the module as stream 1210, while allowingincondensable gases 1208 to exit the module. Stream 1210 is thentransferred to ketone recovery module 300, described with respect toFIG. 3 and the accompanying text, which generates stream 1212 containingthe remaining incondensable gases, and stream 1214 enriched in ketone.

Fermented broth 1205 may be pretreated using a pretreatment module 400,described in FIG. 4 and the accompanying text, which may remove cells,solids, proteins, unconverted sugars and a portion of salts from stream1205, which is then transferred to distillation column 1218, which is alight organics separation module. Distillation column 1218 may removevolatiles such as dissolved incondensable gases, water, ketones andother organics, which leave as an overhead stream that may be combinedwith the stream 1210 entering the ketone recovery module 300 andprocessed accordingly.

Bottom stream 1220 from distillation column 1218 containing glycols andother compounds of interest may then concentrated in a multi effectcolumn system, here only represented by column 1222, which removes awater fraction 1224 as overheads, and a glycol concentrated stream 1225at bottoms. Steam 1225 may be passed to thin-film evaporation module800, described with respect to FIG. 8 and the accompanying text, whichgenerates stream 1226 containing water, stream 1228 enriched in glycoland, if applicable, stream 1230 containing the entrainer and anyresidual salt.

A treatment to remove color and UV absorbing impurities may also beadded to the process in FIG. 12. An activated carbon bed or ahydrogenation reactor may be used for this purpose. In one embodiment,the glycol stream coming from the bottom of distillation column 1222 maybe fed to a hydrogenation reactor where a catalyst uses a small flow ofoxygen to hydrogenate color and UV absorbers contaminants. After thehydrogenation, the flow is sent to feed module 800. In anotherembodiment, the liquid glycol stream from the condenser 816, (withparticular respect to FIG. 8) may be fed to a hydrogenation reactorwhere a catalyst uses a small flow of hydrogen to hydrogenate color andUV absorbers contaminants. After the hydrogenation, glycol may be routedback to distillation column 822 where the light components are removedas overheads 824 and the bottoms 826 are transferred to a to a seconddistillation column 830 where purified glycol is removed as 832 and sentto cooling exchanger and to storage. The heavies from the bottom may besent to burning.

In another embodiment, the liquid glycol stream from condenser 816 issent to an activated carbon bed, where the color and UV absorbersprecursors are adsorbed. After treatment with carbon, and withparticular respect to FIG. 8, glycol may be routed back to distillationcolumn 822 where the light components are removed as overheads 824 andthe bottoms 826 are transferred to a second distillation column 830where purified glycol is removed as 832 and sent to cooling exchangerand to storage. The heavies from the bottom may be sent to burning. Inother embodiments, glycol enriched stream 1228 from module 800 may besent to an activated carbon bed, where the color and UV absorbingcontaminants are absorbed. Then purified glycol is cooled and send tostorage.

While glycol is shown as a representative polyol in this example, it isenvisioned that the process may be adapted to capture other polyolspecies containing two or more available alcohol groups and two or morecarbon atoms, monoethylene glycol or propylene glycol, for example.

Example 4—Salt Removal and Distillation

In the next example, a process in accordance with the present disclosureis used to isolate ketones and glycols from microbial fermentation usingpretreatment/salt removal followed by distillation series.

With particular respect to FIG. 13, fermenter 1302 generates an off-gasstream 1304 that is transferred to absorption module 200, described withrespect to FIG. 2 and the accompanying text, which utilizes input water1306 to absorb ketones and compounds of interest that exit the module asstream 1310, while allowing incondensable gases 1308 to exit the module.Stream 1310 is then transferred to ketone recuperation module 300,described with respect to FIG. 3 and the accompanying text, whichgenerates stream 1312 containing the remaining incondensable gases(which may be recycled back to absorption module 200 in some embodimentsto recover residual ketone), and stream 1314 enriched in ketone.

Fermented broth 1316 may be pretreated using a pretreatment module 400,which may remove cells and solids, and a portion and salts from stream1316, generating stream 1318 after cells, solids and salt removal.

In the pretreatment module 400, the fermented broth coming from thefermenters is first clarified by the methods described above for solids,biomass and organic matter removal. Technologies that can be used arecentrifugation and filtration (microfiltration, ultrafiltration andnanofiltration). Flocculating agents, may be added to increase theefficiency of the solid-liquid separation. In an embodiment, theclarification is done via centrifugation to remove the majority of cellsand other precipitated solids. The solids may be washed to recover theglycol from the cells moisture, following a diafiltration procedure. Amicrofiltration module may be used to remove residual cells debris andfine solid particles. Diafiltration may also be used to recover glycolsfrom retentate. In another embodiment, only microfiltration is used toremove the cells and precipitated solids and water sources such asdiafiltration water can be used to recover the glycol from theretentate. In other embodiment, an ultrafiltration module can be used toremove polysaccharides, proteins and cell debris, and other highmolecular weight compounds.

The clarified stream 1318 is then sent to the salt removal module 900,FIG. 9 and accompanying text, comprising a nanofiltration section toretain residual sugars, multivalent ions, and other high molecularweight compounds and an ion exchange section, passing through a seriesof cationic and anionic exchange modules, eliminating the dissolvedsalts from the stream. In another embodiment, an electrodialysis cellstacks may also be used to remove cations and anions.

Stream 1319, now having a very low concentration of salts, is thentransferred to distillation column 1320, a light organics separationmodule, where volatiles such as ketones and other organics are separatedas an overhead stream 1321 that may be combined with the stream 1310entering the ketone recovery module 300 and processed accordingly.

The bottom stream 1322 from distillation column 1320 containing glycolsand other products of interest may be passed through a multiple effectdistillation columns 1324 (which may be a concentration module in someembodiments) to remove a combined stream 1325 containing water and otherlight organics and generate concentrated stream 1326. Severalconcentration technologies known in the art may be used in addition toor in place of 1324, including multiple effect evaporators or columns,thermal vapor recompression evaporators, or mechanical vaporrecompression (MVR) evaporators, for example.

After the concentration by system 1324, an extra step of salt removalmay be optionally required for polishing. The concentrated stream 1326is then sent to an ion exchange module 1328, passing through a series ofcationic and anionic exchange modules, which may virtually eliminate thedissolved salts from the stream. In some embodiments, electrodialysismembrane modules may be used to remove the cations and anions inaddition to or in place of 1328. Following the ion exchange module 1328,stream 1328 may then be carried to distillation module 500, describedwith respect to FIG. 5 and the accompanying text, where the series ofdistillation columns generates stream 1334 enriched in glycol and astream 1332 containing heavies and other residual components.

A treatment to remove color and UV absorbance impurities may also beadded to the process in FIG. 13. A carbon activated bed or ahydrogenation reactor may be used for this purpose. In one or moreembodiments, the glycol rich stream 1330 coming from ion exchange module1328 may be fed to a hydrogenation reactor where a catalyst uses a smallflow of hydrogen to hydrogenate color and UV absorbers contaminants.After the hydrogenation, stream 1330 may be redirected to distillationmodule 500, where the light components are removed and purified glycolis recovered as 1334. The heavies 1332 may be sent to burning in someembodiments. In some embodiments, glycol stream 1334 may be sent to anactivated carbon bed for polishing to remove odor and color impurities.The purified glycol may then be cooled in an exchanger and sent tostorage. The heavies from the bottom may be sent to burning.

In another embodiment the stream 1330 is sent to an activated carbonbed, where the color and UV absorbers precursors are adsorbed. Thestream is then redirected to distillation module 500 to obtain theglycol stream 1334 and a heavies stream 1332.

While glycol is shown as a representative polyol in this example, it isenvisioned that the process may be adapted to capture other polyolspecies containing two or more available alcohol groups, and two or morecarbon atoms, monoethylene glycol or propylene glycol, for example.

Process Overview

Methods in accordance with the present disclosure are directed to amodular approach for purifying select products from fermenter off-gasand fermented broth. With particular respect to FIG. 14, an overview ofa generalized process flow is shown. Beginning with the initialfermentation chamber 104, off-gas 1402 may be directed to a gasseparating module 200, which removes a portion of incondensable gases,producing stream 1404 containing ketones and other species of interestand potentially residual absorbing agent from gas separation module 200.Stream 1404 is then transferred to a ketone recuperation module 300 toisolate product stream 1406 containing ketones and/or target products.

The fermented broth obtained from fermenter 104 is redirected as stream1408 to pretreatment module 400 where solids and cells are removed,generating fermented clarified broth stream 1410, and then transferredto fluid separation module 1416. In some embodiments, fermentedclarified broth stream 1410 may be processed by a light organicseparation module 1412 (indicated as optional by the dashed line) thatmay separate ketones and other light organics from the fermentedclarified broth. Separated ketones may be redirected as stream 1405 toketone recuperation module in some embodiments to isolate additionalketone. In some embodiments, fermented clarified broth stream 1410 maybe transferred to a concentration module 1414 (indicated as optional bythe dashed line)(with or without processing by light organic separationmodule 1412) to remove water and increase the concentration of ketonesand target products in stream 1410.

Fermented clarified broth stream 1410 is transferred to fluid separationmodule 1416 where glycol and target products are separated as stream1418 from other components in the fermented clarified broth bytechniques discussed above such as reactive distillation, reactiveextraction, evaporation (such as thin film evaporation and/or short pathevaporation), and salt removal followed by distillation series. Productstream 1418 may then be post-treated by color and odor removal module1420 (indicated as optional by the dashed line) in some embodimentsgenerating purified product stream 1422. In some embodiments, color andodor removal module 1420 may be placed upstream of the finaldistillation columns in fluid separation module 1416, such as prior toexiting a reactive distillation module, or a reactive extraction module.

Modeling Simulation

In the following examples, a selected number of processes in accordancewith the disclosure are simulated using Aspen Pius® (Aspen Technology,Inc., Burlington, Mass.).

Example 5: Reactive Distillation Simulation

In this example, a process in accordance with the present disclosure isused to isolate ketones and glycols from microbial fermentation brothusing reactive distillation. With particular respect to FIG. 15, anoff-gas stream 1504 from a fermenter is transferred to module 200(dashed box), described in greater detail in FIG. 2, which containscolumn 204. In column 204, input water 1506 is employed to absorbketones and compounds of interest, which exit as stream 1510.Incondensable gases, including CO₂, N₂, and O₂, leave as 1508.

Stream 1510 follows to the ketone recovery module 300 (dashed box),described in greater detail in FIG. 3 and the accompanying text, whichcontains column 304. In module 300, the majority of the ketone producedis recovered in stream 1514, while the remaining incondensable gasesleave as 1512. In some embodiments, stream 1512 may be recycled back tocolumn 204. The bottoms 1515 of the ketone recovery column 304, whichmay contain the solvent (such as water), acids, and glycols, may be sentto wastewater treatment or may be treated to remove the contaminantsfrom the solvent, which may be recirculated back to the absorptioncolumn 204 in some embodiments.

Fermenters also produce a fermentation broth stream 415 that is directedto distillation column 1518 for removal of volatiles in someembodiments. Volatiles, including incondensable gases, water, ketones,and other organics, may be routed as stream 1516 and combined with 1510to enter the ketone recovery module 304. In some embodiments, stream 415may be pretreated using a pretreatment module (not shown, but such asthat described in FIG. 4) to remove cells, insoluble solids, and saltsprior to transfer.

The bottoms 1520 from column 1518, containing glycols and other productsof interest, are transferred to another distillation step includingcolumn 1522 for partial removal of water. This can be accomplished bysingle or multiple effect distillation columns, or by a series ofevaporators, depending on the feasibility of removing water withoutsignificant loss of products; in this example, one column wassufficient.

Optionally, as described above, after the concentration step, the glycolenriched stream 1525 from the bottom of 1522 may be sent to ahydrogenation reactor (not shown) where a catalyst uses a small flow ofoxygen to hydrogenate color contaminants and UV absorbers. Subsequently,after optional hydrogenation, glycol rich stream 606 may be sent to areactive distillation module 600 (dashed box) described in greaterdetail in FIG. 6 and the accompanying text. In one or more embodiments,stream 1525 is sent to an activated carbon bed, which is also capable ofreducing color and odor. Removal of color and UV absorbers contaminantsfrom glycol enriched stream 1525 may also be performed in an activatedcarbon bed following module 600.

In this example, however, the hydrogenation step was not performed, andbottoms 1525 followed directly to reactive distillation column 604 inmodule 600. Stream 606 includes carbonyl species that are introducedinto column 604, which are then reacted with the glycol to form anacetal. Unreacted carbonyl, as well as acetal and other lightcomponents, were obtained in the top of column 604, exiting as stream608. The bottoms 610, which may be considered a waste stream in someembodiments, include small quantity of unreacted glycol and otherheavies.

Stream 608 is sent to an intermediate distillation step, performed bycolumn 612 where the carbonyl species are separated as the top stream614 of the column, while the rest of the mixture exit at the bottom instream 616 and follows to the hydrolysis column 618. Stream 614 isrecycled back to column 604 and mixed with a fresh carbonyl make-upstream, giving rise to stream 606.

In addition to stream 616, water also is fed in column 618 as stream620, and reacts with acetal to recover glycol. The original carbonylspecies, also produced in this step, exit column 618 as stream 622,together with unconverted acetal and lights. The bottoms, leaving as624, contain mainly water and glycol. Stream 622 may be recycled back tocolumn 604, but it was not considered in this example.

Glycol from stream 624 is concentrated in column 626, where water leavesas a light contaminant in stream 1526. The bottoms 1528 correspond toenriched glycol, which may be further purified in additionaldistillation steps. While glycol is shown as a representative polyol inthis example, it is envisioned that the process may be adapted tocapture polyol species containing two or more available alcohol groupsand two or more carbon atoms, such as monoethylene glycol and propyleneglycol.

In this example, numeric values were attributed to the process to betterillustrate how the separation sequence takes place, and thecorresponding mass balances were organized in Tables 1 to 3. As thefocus is on the recovery of ketones and glycols, only modules 200, 300,and 600 were represented, in such a way that stream 415 corresponds tothe clarified fermented broth exiting module (400 in FIG. 4), and stream1504 related to the off-gas produced in the fermenter.

TABLE 1 Mass balance in modules 200 and 300 in Example 5 Streams 15041506 1508 1510 1514 1512 1515 Component mass flow (kg/hr) Acetone 208.000 5.47 202.52 284.66 25.15 0.16 IPA 104.80 0 0 104.80 0.004 0 304.91Water 171.20 15000 198.51 14972.69 1.34 0.10 19016.68 Glycol 0.07 0 00.07 0 0 0.07 Acetic acid 6.4 0 0 6.4 0 0 50.69 Formic acid 2.4 0 0 2.40 0 31.09 Phenol 0.037 0 0 0.037 0 0 74.08 Glycerol 0 0 0 0 0 0 0.00 CO21526.38 0 1523.78 2.60 0.228 2.371 0.00 N2 4899.14 0 4898.96 0.18 0.0010.178 0.00 O2 1081.59 0 1081.51 0.08 0.001 0.08 0.00 Carbonyl 0.00 0 0 00 0 0.00 Acetal 0.00 0 0 0 0 0 0.00 Sugars + salts 0 0 0 0 0 0 0.00

TABLE 2 Mass balance in module 600 in Example 5 Streams 415 1516 15201524 1525 606 make-up 608 610 Component mass flow (kg/hr) Acetone 109.27107.44 1.83 1.82 0.01 0 0 0.01 0.00 IPA 205.90 200.12 5.79 5.70 0.09 0 00.09 0.00 Water 6270.92 4045.43 2225.50 1092.97 1132.53 0 0 296.801026.52 Glycol 821.79 0.00 821.79 0.14 821.66 0 0 0 164.33 Acetic acid124.62 44.29 80.34 22.22 58.12 0 0 0.03 58.09 Formic acid 46.06 28.6917.37 8.02 9.35 0 0 1.94 7.41 Phenol 195.06 74.04 121.02 19.13 101.89 00 1.92 99.97 Glycerol 15.35 0.00 15.35 0.00 15.35 0 0 0 15.35 CO2 0 0 00 0 0 0 0 0 N2 0 0 0 0 0 0 0 0 0 O2 0 0 0 0 0 0 0 0 0 Carbonyl 0 0 0 0 05832.68 467 5366.15 0.00 Acetal 0 0 0 0 0 0 0 933.07 0.00 Sugars + salts1211.02 0.00 1211.02 0.00 1211.02 0 0 0 1211.02

TABLE 3 Mass balance in module 600 in Example 5 (continued) Streams 614616 620 622 624 1526 1528 Component mass flow (kg/hr) Acetone 0.00 0.010 0.01 0.00 0 0 IPA 0 0.09 0 0.09 0.00 0 0 Water 0.19 296.61 763.3416.34 871.91 871.91 0 Glycol 0 0 0 0 591.59 0.12 591.47 Acetic acid 0.000.03 0 0.00 0.029 0.029 0 Formic acid 0 1.94 0 0.04 1.90 1.90 0 Phenol 01.92 0 0.004 1.92 1.89 0.031 Glycerol 0 0 0 0 0 0 0 CO2 0 0 0 0 0 0 0 N20 0 0 0 0 0 0 O2 0 0 0 0 0 0 0 Carbonyl 5365.81 0.33 0 420.22 0 0 0Acetal 0 933.07 0 93.30 0 0 0 Sugars + salts 0 0 0 0 0 0 0

Example 6: Reactive Extraction

In the next example, separation of glycols and ketones from themicrobial fermentation broth is performed by reactive extraction. Whileconceptually similar to reactive distillation, reactive extractiondiffers by the method by which acetal is isolated from the mixture. Inboth cases, a carbonyl species is introduced converting glycol into anacetal. However, reactive extraction utilizes solvent addition toextract the acetal at the organic phase.

Solvents employed in this operation should be selected considering theiraffinity with the acetal produced, facilitating partition from theaqueous phase; solvent may include mutual solvents having partialmiscibility with water. Possible options include toluene, ethylbenzeneand o-xylene. In some embodiments, the organic phase—solvent, acetal,carbonyl and other contaminants—leaves the column as a top stream, whilethe aqueous—water, solubilized salts and sugars, part of theorganics—remain at the bottom.

With particular respect to FIG. 16, an off-gas stream 1604, generatedduring fermentation, is transferred to absorption module 200 (dashedbox) described in greater detail in FIG. 2 and the accompanying text.Column 204 within module 200 utilizes input water 1606 to absorb ketonesand other compounds, which exit as stream 1610. Incondensable gases 1608are also obtained as products from the absorption column 204.

Stream 1610 is then directed to module 300 (dashed box), where theketone is recovered as described in FIG. 3 and the accompanying text(represented as column 304 in this example). Most of the ketone productis obtained in stream 1614, while remaining incondensable gases leave in1612 (in some embodiments, this stream may be recycled back to module200). The bottoms 1615 of the ketone recovery column 304, which maycontain the solvent (such as water), acids, and glycols, may be sent towastewater treatment or may be treated to remove the contaminants fromthe solvent, which may be recirculated back to the absorption column 204in some embodiments.

Broth stream 415 may be obtained from a fermenter and sent to column1618, where volatiles present in the liquid mixture are stripped andobtained as 1616. This stream may be sent to column 304 in order tofurther concentrate the ketone products. In some embodiments, stream 415may be pretreated using a pretreatment module (not shown, but 400 inFIG. 4) to remove cells and a portion of solids and salts prior totransfer.

The bottoms 1620, including glycols and other products of interest, aretransferred to distillation column 1622, where part of the water presentis removed as 1624. This concentration step can be accomplished eitherby single or multiple effect distillation columns, or by a series ofevaporators, depending on the feasibility of removing water withoutsignificant loss of products; in this example, one column wassufficient. A stream enriched in glycols is obtained as a bottomsproduct, 1625.

While not illustrated, in some configurations, glycol enriched stream1625 may be sent to a hydrogenation reactor after the concentrationstep, where a catalyst uses a small flow of oxygen to hydrogenate colorcontaminants and UV absorbers.

Subsequently, glycol enriched stream 1625 may be sent to a distillationcolumn such as 704, represented in module 700, described in greaterdetail in FIG. 7 and the accompanying text. While also not illustrated,it is envisioned that stream 1625 is sent to an activated carbon bedprior to distillation column 704, which is also capable of reducingcolor and odor. Removal of color and UV absorbing contaminants fromglycol enriched stream 1625 may also be performed in an activated carbonbed following module 700.

In this specific example, however, the optional hydrogenation step wasnot performed, and bottoms 1625 are transferred directly to reactiveextraction column 704 in module 700, as described in FIG. 7 andaccompanying text. Stream 706 including carbonyl species was introducedin the column, where it reacted with glycol to form acetal. Solvent 708was added to the equipment to simultaneously extract acetal from theliquid mixture, essentially in the organic phase.

Acetal, unreacted carbonyl, solvent, and other organics exit the columnas 710, while water, unreacted glycol, solubilized salts and sugars areobtained as bottoms 731. The aqueous phase 731 was transferred todistillation column 732, equipped with condenser and a decanter 736,which partially recovers solvent. For example, bottoms 731 may beseparated into an overhead stream 733, which may be cooled using heatexchanger 734 and passed to decanter 736 to separate the overhead stream733 into a fraction 738 containing organics such as aldehydes, ketones,acetals, and solvent, and a water fraction 740. Water and other heaviesthat exit column 732 as the bottoms may be recovered as stream 742.

The organic stream 710 from column 704 follows to distillation column712, where heavy components, like solvent and unreacted glycol, exit asstream 714. Light components such as the carbonyl species and acetal areremoved as 716, which is sent to the reactive distillation column 720.In some embodiments, stream 714 is recycled back to the column 704.

In column 720, water is introduced as 718, and reacts with acetal torecover glycol and the original carbonyl species. The carbonyl, as wellas unreacted acetal, leave as top steam 724, while a glycol enrichedstream 722 is obtained in the bottom. In some embodiments, stream 724 isrecycled back to column 704.

Finally, stream 722 is sent to column 726 for further concentration ofglycol. Water and other light components are removed in 1626, whileglycol exits as 1628. This stream may be processed in subsequentdistillation columns for obtainment of a purer product. While glycol isshown as a representative polyol in this example, it is envisioned thatthe process may be adapted to capture polyol species containing two ormore available alcohol groups and two or more carbon atoms, such asmonoethylene glycol and propylene glycol.

In the example, numeric values were attributed and simulated using AspenPlus® to better illustrate how the separation sequence takes place, andthe corresponding mass balances are organized in Tables 4 to 8. As thefocus is on the recovery of ketones and glycols, only modules 200, 300,and 700 were represented, in such a way that stream 415 corresponds tothe clarified fermented broth exiting module (400 in FIG. 4), and stream1604 related to the off-gas produced in the fermenter.

TABLE 4 Mass balance for modules 200 and 300 in Example 6 Streams 16041606 1608 1610 1612 1614 1615 Components mass flow (kg/hr) Acetone208.00 0 5.473 202.52 0.29 309.67 0 IPA 104.80 0 0 104.80 0.11 304.81 0Water 171.20 15000 198.51 14972.69 0.078 2462.01 16556.028 Glycol 0.0660 0 0.066 0 0 0.066 Acetic acid 6.40 0 0 6.40 0 0 50.69 Formic acid 2.400 0 2.40 0 2.905 28.18 Phenol 0.037 0 0 0.037 0 58.27 15.81 Glycerol 0 00 0 0 0 0 CO2 1526.38 0 1523.78 2.60 0.64 1.96 0 N2 4899.14 0 4898.960.18 0.16 0.016 0 O2 1081.59 0 1081.51 0.076 0.065 0.011 0 Carbonyl 0 00 0 0 0 0 Toluene 0 0 0 0 0 0 0 Acetal 0 0 0 0 0 0 0 Sugars + salts 0 00 0 0 0 0

TABLE 5 Mass balance for columns 1618 and 1622 in Example 6 Streams 4151616 1620 1624 1625 Components mass flow (kg/hr) Acetone 109.27 107.441.83 1.82 0.01 IPA 205.90 200.12 5.79 5.70 0.09 Water 6270.92 4045.432225.50 1092.97 1132.53 Glycol 821.79 0 821.79 0.14 821.66 Acetic acid124.62 44.29 80.34 22.22 58.12 Formic acid 46.06 28.69 17.37 8.02 9.35Phenol 195.06 74.04 121.02 19.13 101.89 Glycerol 15.35 0 15.35 0 15.35CO2 0 0 0 0 0 N2 0 0 0 0 0 O2 0 0 0 0 0 Carbonyl 0 0 0 0 0 Toluene 0 0 00 0 Acetal 0 0 0 0 0 Sugars + salts 1211.02 0 1211.02 0 1211.02

TABLE 6 Mass balance for columns 704 and 712 for Example 6 Streams 706708 710 731 714 716 Components mass flow (kg/hr) Acetone 0 0 0.01 0.00 00.01 IPA 0 0 0.076 0.009 0 0.076 Water 0 0 363.92 959.39 214.29 149.63Glycol 0 0 88.80 75.54 88.80 0 Acetic acid 0 0 38.90 19.22 38.90 0Formic acid 0 0 5.10 4.25 5.03 0.072 Phenol 0 0 100.19 1.70 100.19 0Glycerol 0 0 9.24 6.12 9.24 0 CO2 0 0 0 0 0 0 N2 0 0 0 0 0 0 O2 0 0 0 00 0 Carbonyl 5832.64 0 5366.10 0 0 5366.10 Toluene 0 1000 999.03 0.97996.75 2.28 Acetal 0 0 933.07 0 1.24 931.83 Sugars + salts 0 0 01211.017 0 0

TABLE 7 Mass balance for columns 720 and 726 in Example 6 Streams 718724 722 1626 1628 Components mass flow (kg/hr) Acetone 0 0.01 0 0 0 IPA0 0.076 0 0 0 Water 760.85 119.01 619.99 0 619.99 Glycol 0 0 590.80585.85 4.95 Acetic acid 0 0 0 0 0 Formic acid 0 0.018 0.054 0 0.054Phenol 0 0 0 0 0 Glycerol 0 0 0 0 0 CO2 0 0 0 0 0 N2 0 0 0 0 0 O2 0 0 00 0 Carbonyl 0 5785.43 0 0 0 Toluene 0 2.28 0 0 0 Acetal 0 93.18 0 0 0Sugars + salts 0 0 0 0 0

TABLE 8 Mass balance for columns 732 and 736 in Example 6 Streams 742733 738 740 Components mass flow (kg/hr) Acetone 0 0.001 0 0.001 IPA 00.009 0 0.009 Water 910.97 48.43 0.002 48.42 Glycol 75.54 0 0 0 Aceticacid 18.91 0.30 0 0.30 Formic acid 4.04 0.21 0 0.21 Phenol 1.61 0.090.001 0.09 Glycerol 6.12 0 0 0 CO2 0 0 0 0 N2 0 0 0 0 O2 0 0 0 0Carbonyl 0 0 0 0 Toluene 0 0.97 0.77 0.19 Acetal 0 0 0 0 Sugars + salts1211.02 0 0 0

Example 7: Thin-Film Evaporation

In the next example, a process in accordance with the present disclosureis used to isolate ketones and glycols from the microbial fermentationbroth using thin-film evaporation. With particular respect to FIG. 17, afermented broth is transferred as stream 415 to distillation column1718. In some embodiments, stream 415 may be processed by a pretreatmentmodule (not shown) such as that described in FIG. 4 and accompanyingtext to remove cells and insoluble solids. However, in some embodiments,broth from fermentation may be fed directly into column 1718.Distillation column 1718 separates light components—including ketones—astop product 1716, while heavies, such as glycol, exit as 1720.

Stream 1716 is then sent to module 300 (represented as a dashed box anddescribed above with respect to FIG. 3 and the accompanying text), wherecolumn 304 separates ketones as 1714, while heavy organics and waterleave as 1715 and a small quantity of non-condensable gases leave as1712. In some embodiments, this stream may be recycled back to module200. The bottoms 1715 of the ketone recovery column 304 may be sent towastewater treatment or may be treated to remove the contaminants fromthe solvent, which may be recirculated back to the absorption column 204in some embodiments.

In addition, off-gas stream 1704, generated during fermentation, istransferred to absorption module 200, which is described in FIG. 2 andthe accompanying text. Column 204 within module 200 utilizes input water1706 to absorb ketones and other compounds, which exit as stream 1710.Incondensable gases 1708 are also obtained as products from theabsorption column 204. In column 304, stream 1710 is also processed,including liquid products recovered in adsorption column 204, whichseparates them from incondensable gases contained in the fermentationoff-gas.

Glycol present in stream 1720 is directed to column 1722 as apre-concentration step. This can be accomplished either by single ormultiple effect distillation columns, or by a series of evaporators,depending on the feasibility of removing water without significant lossof products; in this example, one column was sufficient. A streamenriched in glycols is obtained as a bottoms product, 1725, while waterleaves as 1724.

While not illustrated, in some configurations, glycol enriched stream1725 may optionally be sent to a hydrogenation reactor after theconcentration step, where a catalyst uses a small flow of oxygen tohydrogenate color contaminants and UV absorbers. Subsequently, glycolenriched stream 1725 may be sent to a thin-film evaporator such as 812,represented in module 800, described with respect to FIG. 8 and theaccompanying text. While not illustrated, it is envisioned that stream1725 may be sent to an activated carbon bed, which is also capable ofreducing color and odor, prior to thin-film evaporator 812. Removal ofcolor and UV absorbers contaminants can also be performed in anactivated carbon bed following module 800, that is, processing glycolenriched stream 1725.

In this specific example, however, the hydrogenation step was notperformed, and bottoms 1725 followed directly to thin-film evaporator812 in module 800, as described in FIG. 8 and accompanying text. A saltentrainer is also added to 812 as make-up stream 810. Stream 814obtained as overhead, rich in glycol, is sent to partial condenser 816,where light organics and water exit as 818. Stream 820 is the heavierproduct from partial condenser 816. It comprises glycol and is fed intoto distillation column 822, where light contaminants are further removedas stream 824.

The bottoms 826 from distillation column 822 are sent to column 830 forremoval of heavier organics, which exit as 1728, and purified glycol isobtained as 1726. While glycol is shown as a representative polyol inthis example, it is envisioned that the process may be adapted tocapture polyol species containing two or more available alcohol groupsand two or more carbon atoms, such as monoethylene glycol and propyleneglycol.

Stream 836, also produced in thin-film evaporator 812, constitutes amixture of entrainer, residual glycol, sugars and salts. In order torecover the entrainer, this stream is sent to the second thin-filmevaporator 838, which operates at low pressure. Sugars and salts exit inthe liquid phase as 844, considered a waste stream in some embodiments.Residual glycol and entrainer are removed as 842-1, later cooled down inheat exchanger 840, and recycled back to thin-film evaporator 812 as842-2.

In this example, numeric values were attributed and simulated usingAspen Plus® to better illustrate how the separation sequence takesplace, and the corresponding mass balances are organized in Tables 9 to12. As the focus is on the recovery of ketones and glycols, only modules200, 300, and 800 were represented, in such a way that stream 415corresponds to the clarified fermented broth exiting module (400 in FIG.4), and stream 1704 related to the off-gas produced in the fermenter.

TABLE 9 Mass balance for modules 200 and 300 in Example 7 Streams 17041706 1708 1710 1712 1714 1715 Component mass flow (kg/h) Acetone 208.000 5.43 202.56 25.77 283.96 0.27 IPA 104.80 0 0.28 104.52 0 0.005 303.66H2O 171.20 15000 198.82 14972.38 0.10 1.34 19017.29 Glycol 0.07 0 00.066 0 0 0.066 Acetic acid 6.40 0 0 6.40 0 0 50.78 Formic acid 2.40 0 02.40 0 0 31.09 Phenol 0.04 0 0 0.037 0 0 74.02 Entrainer 0 0 0 0 0 0 0CO2 1526.38 0 1523.72 2.66 2.43 0.23 0 N2 4899.14 0 4898.96 0.18 0.180.001 0 O2 1081.59 0 1081.51 0.077 0.077 0.001 0 Sugars + salts 0 0 0 00 0 0

TABLE 10 Mass balance for columns 1718 and 1724 in Example 7 Streams 4151716 1720 1724 1725 Component mass flow (kg/h) Acetone 109.27 107.441.83 1.82 0.01 IPA 205.90 199.15 6.75 6.54 0.21 H2O 6270.92 4046.352224.57 1099.91 1124.66 Glycol 821.79 0 821.79 0.18 821.62 Acetic acid124.62 44.38 80.24 19.82 60.43 Formic acid 46.06 28.69 17.37 2.36 15.01Phenol 195.06 73.99 121.08 19.38 101.70 Entrainer 15.35 0 15.35 0 15.35CO2 0 0 0 0 0 N2 0 0 0 0 0 O2 0 0 0 0 0 Sugars + salts 1211.02 0 1211.020 1211.02

TABLE 11 Mass balance for 812 and 838 in Example 7 Streams 810 814 836842-1 844 842-2 Component mass flow (kg/h) Acetone 0 0.01 0 0 0 0 IPA 00.21 0 0 0 0 H2O 0 1124.59 6.06 5.99 0.07 5.99 Glycol 0 801.15 157.17136.70 20.47 136.70 Acetic acid 0 60.42 0.51 0.50 0.01 0.50 Formic acid0 15.01 0.08 0.07 0.001 0.07 Phenol 0 101.00 8.31 7.61 0.71 7.61Entrainer 100 10.13 138.83 33.60 105.22 33.60 CO2 0 0 0 0 0 0 N2 0 0 0 00 0 O2 0 0 0 0 0 0 Sugars + salts 0 0.015 1213.36 2.36 1211.00 2.36

TABLE 10 Mass balance for 816, 822, and 830 in Example 7 Streams 818 820824 826 1726 1728 Component mass flow (kg/h) Acetone 0.01 0 0 0 0 0 IPA0.07 0.13 0.13 0 0 0 H2O 364.47 760.13 7604.13 0 0 0 Glycol 1.73 799.4125.23 774.19 760.00 14.19 Acetic acid 8.51 51.91 51.91 0 0 0 Formic acid1.43 13.58 13.58 0 0 0 Phenol 1.97 99.03 99.02 0.003 0.003 0 Entrainer 010.13 0 10.13 0 10.13 CO2 0 0 0 0 0 0 N2 0 0 0 0 0 0 O2 0 0 0 0 0 0Sugars + salts 0 0.015 0 0.015 0 0.015

Although the preceding description is described herein with reference toparticular means, materials and embodiments, it is not intended to belimited to the particulars disclosed herein; rather, it extends to allfunctionally equivalent structures, methods and uses, such as are withinthe scope of the appended claims. In the claims, means-plus-functionclauses are intended to cover the structures described herein asperforming the recited function and not only structural equivalents, butalso equivalent structures. Thus, although a nail and a screw may not bestructural equivalents in that a nail employs a cylindrical surface tosecure wooden parts together, whereas a screw employs a helical surface,in the environment of fastening wooden parts, a nail and a screw may beequivalent structures. It is the express intention of the applicant notto invoke 35 U.S.C. § 112(f) for any limitations of any of the claimsherein, except for those in which the claim expressly uses the words‘means for’ together with an associated function.

What is claimed is:
 1. A method of obtaining ketones from a fermentationprocess, the method comprising: collecting an off-gas and a fermentedbroth from a fermenter, wherein the off-gas and the fermented broth bothcomprise a ketone; transferring the off-gas from the fermenter to aketone recuperation module and the fermented broth to a fluid separatingmodule; and isolating the ketones from both the off-gas and thefermented broth.
 2. The method of claim 1, further comprising processingthe fermented broth with one or more selected from a group consisting ofactivated carbon bed, hydrogenation, UV treatment, and ion-exchangecolumn.
 3. The method of claim 1, further comprising transferring thefermented broth to a color and odor module prior to or following thefluid separation module.
 4. The method of claim 1, further comprisingtransferring the fermented broth to a concentration module prior totransferring the fermented broth to the fluid separation module.
 5. Themethod of claim 4 wherein the concentration module comprises one or moreselected from a group consisting of distillation columns andevaporators.
 6. The method of claim 1, further comprising transferringthe fermented broth to a pretreatment module prior to transferring thefermented broth to the fluid separation module, and wherein thepretreatment module removes at least a portion of cells and solids fromthe fermented broth.
 7. The method of claim 6, wherein the pretreatmentmodule comprises one or more selected from a group consisting ofcentrifugation, microfiltration, ultrafiltration, and nanofiltration. 8.The method of claim 1, wherein the fluid separating module comprises asalt removal module and one or more distillation columns.
 9. The methodof claim 8, wherein the salt removal module comprises one or moreselected from a group consisting of an ion exchange module, aprecipitation module, an electrodialysis module, and a nanofiltrationmodule.
 10. The method of claim 1, wherein the ketone is acetone. 11.The method of claim 1, further comprising transferring the off-gas fromthe fermenter to a gas separating module prior to transferring theoff-gas to the ketone recuperation module, wherein the gas separatingmodule removes at least a portion of the ketone from the off-gas.
 12. Amethod of obtaining ketones from a fermentation process, the methodcomprising: collecting an off-gas and a fermented broth from thefermenter, wherein the off-gas and the fermented broth both comprise aketone; transferring the off-gas from the fermenter to a ketonerecuperation module; transferring the fermented broth to a light organicseparation module that generates a stream comprising the ketone;transferring the stream comprising the ketone to the ketone recuperationmodule; and isolating the ketone from both the off-gas and the fermentedbroth.
 13. The method of claim 12, further comprising processing thefermented broth with one or more selected from a group consisting ofactivated carbon bed, hydrogenation, UV treatment, and ion-exchangecolumn.
 14. The method of claim 12, further comprising transferring thefermented broth to a color and odor module prior to or following thelight organic separation module.
 15. The method of claim 12, furthercomprising transferring the fermented broth to a concentration moduleprior to transferring the fermented broth to the light organicseparation module.
 16. The method of claim 15 wherein the concentrationmodule comprises one or more selected from a group consisting ofdistillation columns and evaporators.
 17. The method of claim 12,further comprising transferring the fermented broth to a pretreatmentmodule prior to transferring the fermented broth to the light organicseparation module, and wherein the pretreatment module removes at leasta portion of cells and solids from the fermented broth.
 18. The methodof claim 17, wherein the pretreatment module comprises one or moreselected from a group consisting of centrifugation, microfiltration,ultrafiltration, and nanofiltration.
 19. The method of claim 12, whereinthe ketone is acetone.
 20. The method of claim 12, further comprisingtransferring the off-gas from the fermenter to a gas separating moduleprior to transferring the off-gas to the ketone recuperation module,wherein the gas separating module removes at least a portion of theketone from the off-gas.
 21. A method of obtaining glycols from afermentation process, the method comprising: collecting a fermentedbroth from the fermenter, wherein the fermented broth comprises aglycol; transferring the fermented broth to a fluid separating modulethat comprises a reactive distillation column; and isolating the glycolfrom the fermented broth, wherein isolating the glycol comprises:reacting a glycol in the fermented broth in the reactive distillationcolumn with a separating agent to form an acetal and collecting a streamfrom the reactive distillation column comprising the acetal;transferring the stream comprising the acetal to a distillation columnand distilling the stream comprising the acetal; transferring the streamcomprising the acetal from the distillation column to a hydrolysiscolumn and hydrolyzing the acetal to yield a reverted glycol; andcollecting a stream from the hydrolysis column comprising the revertedglycol.
 22. The method of claim 21, wherein the glycol is monoethyleneglycol.
 23. The method of claim 21, wherein the fluid separating modulecomprises a first evaporator, and wherein the fermented broth comprisesa salt entrainer; wherein the method further comprises: collecting astream from the first evaporator comprising a glycol.
 24. The method ofclaim 23, wherein the salt entrainer is glycerol or sugar.
 25. Themethod of claim 23, further comprising: transferring the stream from thefirst evaporator to a second evaporator; collecting a stream from thesecond evaporator comprising a glycol.
 26. The method of claim 23,comprising processing the stream from the first evaporator to remove oneor more selected from a group consisting of water salt entrainer, heavyorganics, and light organics.
 27. The method of claim 23, wherein theevaporator is a thin film evaporator or a short path evaporator.
 28. Themethod of claim 21, comprising processing the fermented broth with oneor more selected from a group consisting of activated carbon bed,hydrogenation, UV treatment, and ion-exchange column.
 29. The method ofclaim 21, comprising transferring the fermented broth to a color andodor module prior to or following the fluid separating module.
 30. Themethod of claim 21, further comprising transferring the fermented brothto a concentration module prior to transferring the fermented broth tothe fluid separating module.
 31. The method of claim 30, wherein theconcentration module comprises one or more selected from a groupconsisting of distillation columns and evaporators.
 32. The method ofclaim 21, further comprising transferring the fermented broth to apretreatment module prior to transferring the fermented broth to thefluid separating module, and wherein the pretreatment module removes atleast a portion of cells and solids from the fermented broth.
 33. Themethod of claim 32, wherein the pretreatment module comprises one ormore selected from a group consisting of centrifugation,microfiltration, ultrafiltration, and nanofiltration.
 34. The method ofclaim 21, wherein the fluid separating module comprises a salt removalmodule.
 35. The method of claim 34, wherein the salt removal modulecomprises one or more selected from a group consisting of an ionexchange module, a precipitation module, an electrodialysis module, anda nanofiltration module.
 36. The method of claim 21, further comprisingcollecting a stream comprising the separating agent from the hydrolysiscolumn; and recycling at least a portion of the stream comprising theseparating agent back to the reactive distillation column.